Sun's activity controls Greenland temperatures

July 16, 2015

A new study found that Greenland temperatures fell from the 1970s through the early 1990s while temperatures across much of the rest of the Northern Hemisphere rose. This map shows the average difference in surface temperatures between 1920-1940 and 1975-1995. Grey areas indicate regions where not enough data was available to calculate long-term temperature changes. Credit: Takuro Kobashi

The sun's activity could be affecting a key ocean circulation mechanism that plays an important role in regulating Greenland's climate, according to a new study. The phenomenon could be partially responsible for cool temperatures the island experienced in the late 20th century and potentially lead to increased melting of the Greenland ice sheet in the coming decades, the new research suggests.

Scientists have sought to understand why Greenland cooled during the 1970s through the early 1990s while most of the Northern Hemisphere experienced rising temperatures as a result of greenhouse warming.

The new study suggests high solar activity starting in the 1950s and continuing through the 1980s played a role in slowing down ocean circulation between the South Atlantic and the North Atlantic oceans. Combined with an influx of fresh water from melting glaciers, this slow-down halted warm water and air from reaching Greenland and cooled the island while temperatures rose across the rest of the Northern Hemisphere, according to the new study accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union.

The new research also suggests weak solar activity, like the sun is currently experiencing, could slowly fire up the ocean circulation mechanism, increasing the amount of warm water and air flowing to Greenland.

Starting around 2025, temperatures in Greenland could increase more than anticipated and the island's ice sheet could melt faster than projected, according to Takuro Kobashi, a climate scientist with the Department of Climate and Environmental Physics at the University of Bern in Switzerland and lead author of the new study.

This unexpected ice loss would compound projected sea-level rise expected to occur as a result of climate change, Kobashi said. The melting Greenland ice sheet accounted for one-third of the 3.2 millimeters (0.13 inches) rise in global sea level every year from 1992 to 2011.

"We need to really consider how solar activity will change in the future," said Kobashi. "If solar activity becomes really low, as scientists expect, the Greenland ice sheet will melt faster than we expected from the climate model with just greenhouse gas [warming]."

The new study compared past solar activity with historical temperature records to figure out if the cooling Greenland experienced during the late 20th century was part of a long-term pattern.

The team used ice cores drilled from the Greenland ice sheet to reconstruct snow temperatures for the past 2,100 years. A relatively new technique, which measures argon and nitrogen gases trapped in the ice, allowed the scientists to measure small changes in temperature at 10- to 20-year increments.

The ice cores showed that for the past 2,000 years changes in Greenland temperatures have generally followed any temperature shifts occurring in the Northern Hemisphere. The new research found that the change in Greenland temperatures vacillated up and down around the average change in Northern Hemisphere temperatures over time. The vacillations coincided with changes in the sun's energy output that occurred over multiple decades, according to the new study.

The authors of a new paper placed ice from subsections of Greenland ice cores in glass flasks. Under a vacuum, the ice melted, releasing the air trapped within the ice. The scientists used the trapped air to calculate the island’s temperatures for the past 2,100 years and compare them to vacillations in solar activity. Credit: Takuro Kobashi

When the sun's energy output increased, there was a bigger drop in Greenland's temperature compared to the change in average temperature across the Northern Hemisphere. When the sun's energy output decreased, there was a larger increase in Greenland's temperature compared to the change in average temperature that occurred across the Northern Hemisphere.

Climate models showed that changes in solar activity could prompt shifts in ocean and air circulation in the North Atlantic that affect Greenland's climate, according to the new study.

Shifting circulation patterns

Water circulation in the Atlantic follows a steady pattern of movement, called the Atlantic Meridional Overturning Circulation (AMOC). Warm water flows from the South Atlantic toward the North Atlantic, transferring heat toward Greenland. As the water cools, it sinks to the ocean floor and travels south toward the tropics, completing the circular pattern.

During a period of high solar activity, more energy from the sun reaches Earth and is transferred to tropical waters. When this warmer-than-usual water reaches the North Atlantic, it is not dense enough to sink. With nowhere to go, the water causes a traffic jam and the water circulation pattern slows down.

Changes in solar activity can also alter the atmospheric circulation pattern over the Atlantic, which in turn affects ocean circulation, but how this process works is still unknown, said Kobashi.

In the late 20th century, there also was a compounding problem. Large amounts of freshwater gushed into the North Atlantic as climate change caused increased melting of glaciers, icebergs, and the Greenland ice sheet. Freshwater, being more buoyant than salt water, entered the intersection where cool water drops to the ocean floor and travels south to the tropics. Climate models showed that the water in the intersection became less salty and less likely to sink. Models also showed that additional freshwater came from an increase in rainfall, according to the new study.

The traffic jam worsened and the water circulation pattern that transfers heat from the South Atlantic to the North Atlantic slowed. This slow-down caused the air above Greenland to cool and temperatures there to drop, according to the new study.

Because the oceans take a long time to heat up or cool down, the temperature changes in Greenland lagged 10 to 40 years behind the high solar activity, showing up from the 1970s through the early 1990s, according to the new study.

The new study suggests low solar activity could have the opposite effect and lead to warmer temperatures in Greenland in another decade. When there is less solar energy reaching the Earth, water reaching Greenland easily sinks and returns to the tropics along the ocean floor. The water circulation pattern speeds up, quickly funneling heat toward Greenland and warming the island.

Greenhouse gases versus solar activity

The new study makes a good case that the solar maximum in the 1950s through the 1980s may have played a role in the cooling Greenland saw in the late 20th century, said Michael Mann, a climate scientist with the Department of Meteorology at Penn State University in University Park, Pennsylvania, who was not involved in the new study.

Another recent study by Mann and his colleagues proposed that trapped greenhouse gases from fossil fuel burning caused warming across the Northern Hemisphere and triggered an increase in ice melt. This led to the slowdown in ocean circulation and a cooler Greenland.

Both studies suggest buoyant meltwater from melting glaciers would have interrupted the sinking of the AMOC and its return to the tropics along the bottom of the ocean. But the new research suggests solar activity is the main driver behind the changes to the ocean circulation pattern.

"I'm open-minded that the real answer is more complicated, and it may be a combination of the two hypotheses," said Mann. "This article paves the way for a more in-depth look at what is going on. The challenge now will be teasing apart the two effects and trying to assess the relative importance of both of them."

Kobashi contends that solar activity explains the change in ocean circulation and Greenland warming since 1995, which he says cannot be explained by increasing greenhouse gases alone.

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This article is speculative. It tries to conclude that a decrease in solar activity will lead to global warming -- and on the basis of a very thin understanding of what causes these circulation patterns. They are guessing.

Fact is that the circulation patterns are related to the sudden stratospheric warming events (SSW) -- and that raises important questions about how such a thin atmosphere (the tail) can wag the dense ocean (the dog). There is a 1000x energy content difference.

Piers Corbyn claims to be able to predict the SSW's based upon solar/lunar activity/cycles, and NASA appears to be taking him at his word by funding attempts to create models which do just that (they call it electric joule heating).

This hot water rises and cold water sinks approach to these circulation patterns looks like it will eventually be ditched as an insufficient explanation.

docile

docile

docile, Did you click on "more' Under the map ?If not here is what you missed "This map shows the average difference in surface temperatures between 1920-1940 and 1975-1995. Grey areas indicate regions where not enough data was available to calculate long-term temperature changes

Note HIGHER not 'lower' insolation which created a LOCAL not 'global' temp gradient effect and slowed the relevant 'ocean circulation' currents bringing warmer water keeping Greenland at previous temps:

The new study suggests high solar activity starting in the 1950s and continuing through the 1980s played a role in slowing down ocean circulation between the South Atlantic and the North Atlantic oceans. Combined with an influx of fresh water from melting glaciers, this slow-down halted warm water and air from reaching Greenland and cooled the island while temperatures rose across the rest of the Northern Hemisphere...

It's a transient local micro-climate effect; from overall global warm effect due to CO2 forcing exacerbating all sun/other inputs, irrespective of variability. Tease out local versus global aspects; don't miss subtle but important dynamics involved in such local/global observations. :)

Reality, so the article is describing the SUN, but you are still on CO2?Reality check.

I am sorry that when water solidifies it releases so much heat, causing a place that would normally be below 0C to be near 0C, but that's the universe.

That is why, the "Brass Bowl" model I go on about is so useful. The effect of water freezing and melting is more powerful than just about any other effect, except the heat of evaporation, which dominates the Earth. This effect is so profound that climate change has to by-pass it or use it somehow.

of course, you do tend to go on about this... problem is, you didn't account for any outside influences, NOR do you have a control to substantiate your findings, etc etc etc...if your model is so successful, why haven't you published a paper on it? and why do ACTUAL scientists ignore your posts?perhaps there IS a reason... see below:http://phys.org/n...nce.html

@ALCHIEyour gedanken model doesn't even demo key concepts...and now you are backpedaling because you yourself said that your model explains everything (shall i start linking threads where you made this claim?)you also said your model took into account for noise and other factors when i started questioning your rationale (again, do i gotta link it and prove you an idiot AGAIN?)

But you can't publish it

AGAIN ... the reason you can't publish isn't about "novelty", it is about your lack of empirical evidence and your insistence on making unsubstantiated claims, like above

that doesn't work in peer reviewed journalsit only works when you are attempting to push BS to an illiterate who doesn't know any better

You miss the subtle connection/relevance involved mate. The higher solar activity was responsible for warming locally as well as globally adding to overall dynamics being 'shifted' globally by CO2 forcing irrespective of other factors in the usual dynamics. The local effects on Greenland was due to local heating component from increased solar activity, which affected the currents which usually depend on the thermal gradients between local and more southerly ocean waters for the warm ocean water circulation which controls the Greenland microclimate effects either way; ie: when circulation fast, greenland warmer; when slow, greenland cooler. Yes, ice/water/vapor phase/heatload (also albedo, volcanism sun etc), already acknowledged to prolong/complicate/exacerbate such local/global dynamics, BUT ATMOSPHERE CO2 levels 'always on', so is overarching persistent 'net-net' determinant beyond all that. :)

How can modeling the Earth-Sun system as a Sun, candle, and a bowl with water and ice in it, predict climate change?1. Melting icecaps (ice cubes).2. Temperature stability (no not flat-lining, just not a +4C increase), ice keeps temperatures "near 0C".3. Localized effects (where the flame meets the bowl).4. "Climate" (OK it's a bowl, use your imagination) change from ice recession and increase of localized effects.

Less direct, but predictable:5. Rise of the Earth's oceans.6. Increase in number, but not necessarily intensity of Hurricanes. (More energy in the system.)7. More dynamic weather.8. More, this is a primitive model!Now contrast this with CO2, or insulating the planet. Not the same.The question is will ice melting in a brass bowl make these predictions?Absolutely.Is this what we have observed?Yes.

I've finally figured you out. Instead of posting on PO though your "talents" should be applied to satirical scifi/fantasy. You're not very good at it so you would have to self publish ebooks at 99 cents a pop. Eventually you could buy a cup of coffee.

Vietvet,You lost the entire board at "I've finally figured [something] out."You should be a comedian, people like to laugh when people have the good form to depreciate themselves, and you saying you figured anything out, has the forum rolling in the aisles.

I try not to mock anyone who I feel is genuine in their efforts, irrespective of whether they may be wrong for reasons of honest mistakes. :)

Again, the local greenland temps are tied locally to local events/conditions as well as being connected unltimately to ocean currents from further afield which are due to ocean circulation affected globally by warming globally changing the patterns of currents/circulations in ocean and atmos. That is what the above article was about.

As for the overall picture regarding the CO2 concentrations/effects correlation and trajectory, from earlier to present to projected future, if increases in CO2 emissions/concentrations continue as they have been, I have just posted a response to you and john_mathon in...

Further increases in CO2 will increase all those things. I estimate about 3000ppm should begin to affect climate in a noticeable way.Thought the fact that CO2 begins it's work in the upper atmosphere, where it protects the Earth from heating of this kind. The black body (BB) spectrum of the Sun has much more, by magnitude infrared radiation than the Earth.

@ALCHIE/profit and all your other sock puppetsNo, it doesn't "compete", it works WITH and in a feedback cycle... big difference...BUTabout your specific posts above... all you gotta do NOW is to write it all up in a legitimate study with all the requisite empirical evidence, maths and submit this to a reputable peer reviewed journal... sit back and waith for the Nobel prize and massive accolades for your accuracy and hard work! don't forget to add in your brass bowl model, constraints, control and all that data![hyperbole, sarc, satire]

CO2 in the upper atmosphere diffuses or blocks incoming radiation 1000x more than it retains heat near ground. This effect increases with increasing CO2.

What Alche/Waterdummy seems incredibly ignorant of is that the surface of the sun and the surface of the earth are different distances from the atmosphere. Here he is trying to compare the absorption and reemission of IR from the surface of the earth (293 K) and the IR from the surface of the sun (4778 K) without putting distance in the equation. Just a hint, radiant heat transfer is proportional to the inverse square of the distance. Now compare the IR flux from the sun with that from the Earth.

thermodynamics, as usual seems awfully ignorant of the conservation of energy, one of the most basic principles of the physical sciences, and the very simple logic required to work even the most elementary things out for himself.Apparently the Earth is capable of generating heat in excess of the Sun.

Let's all laugh at him through it:Total energy of the Sun in the BB spectrum, call it T.Fraction of that energy heating the Earth at surface level, being converted into a much cooler distribution. Much less.

He somehow believes the energy density on Earth is greater than in outer space. I guess the Earth radiates more power than it takes in!!!

Or let's let him put distance in the equation... which is further? The outer atmosphere or the surface of the Earth?

Lets all give him a laugh for his efforts, and prepare jokes for his backpedaling. I'm guessing that a punchline will be his failure to understand equipartition and equilibrium.

Or let's let him put distance in the equation... which is further? The outer atmosphere or the surface of the Earth?

Hmmmm....

The sun is 1.52 x 10^8 km from the earth.

The upper atmosphere is at about 50 km from the surface of the earth.

We can let Alche/WaterBowl show us why the inverse square law is not brought into his conjectures. How is the inverse square law incorporated into his water bowl. I expect him to dissolve into his remarks about me being a sock puppet and show his fear of the "skeptigoons" (his term) without any technical rebutal. What a moron.

thermodynamics, that's a great point, my gosh you're right, I didn't see that at all! That completely refutes everything I've ever said!In fact, the Sun is too far away to have any influence on the Earth at all!

JK.

My equilibrium preparations, all for moot, thermo fails at something even more elementary. You're a special kind of person, aren't you thermo?

thermodynamics, that's a great point, my gosh you're right, I didn't see that at all! That completely refutes everything I've ever said!

Thanks for admitting how really stupid you are. Now, please explain to us how your water bowl takes the distance to the sun into consideration?

Also, please explain your comment of:

CO2 in the upper atmosphere diffuses or blocks incoming radiation 1000x more than it retains heat near ground. This effect increases with increasing CO2.

Just how does the upper atmosphere "diffuses or blocks incoming radiation 1000x more than it retains heat near the ground when the heat is incoming from the sun and outgoing from the, much closer, Earth. Let's see the math for that...

Hey RealityCheck,RealityCheck-time. One thing I know about the skeptigoon is that they can't change their opinions. They'd probably get fired if they did.But you, see above, The Sun has 1366Watt/m2 distributed over the BB spectrum, The Earth has less that 255watts/m2.The BB spectrum, if you are unfamiliar, means that there is always more of a particular frequency with increasing temperature, despite the peak.

Therefore CO2 must block more heat incoming from the Sun than it does on Earth.

That's math fro the above. Is there any refutation?Also, you never did show me any feedback mechanism that would present the results you spoke of, if you wouldn't mind, could you show me your approach? Thanks.

Well, Lee, if you read the above you'd realize that the skeptigoons have been forced to concede.The proof is simple, and has been. On Earth, where CO2 takes second fiddle to water vapor, CO2 acts to cool the Earth.

Water Vapor drops greatly above 6km. CO2 does not.CO2 stops incoming Solar radiation which is about 6x stronger in it's frequency band than Terrestrial radiation.

Therefore, Water vapor stops the overwhelming bulk of Terrestrial Radiation, so CO2 has no effect. Above the 6km, it blocks solar.